Localization of a collagenous protein in the organic matrix of spicules from the octocoral Leptogorgia virgulata (Cnidaria: Gorgonacea)
Date of Award
Master of Science
Dr. Roni J. Kingsley
Dr. W. John Hayden
Dr. Gary P. Radice
Calcareous body inclusions are commonly found throughout the invertebrate taxa. Elaborately structured calcium carbonate spicules are the major mineralized body inclusions of the gorgonian, Leptogorgia virgulata. Spicule formation in this octocoral, as well as other calcium carbonate invertebrate structures, is apparently regulated by the intra-spicule organic matrix. Recent findings show that the insoluble fraction of the spicule organic matrix is collagenous. Collagen, although integral to calcium phosphate structures found in vertebrates is not usually associated with the formation of invertebrate calcium carbonate structures. Interestingly, collagen is present in the organic matrix during the summer but absent in winter. This suggests that there is a seasonal turnover of collagen. Antibodies (supplied by Dr. N. Watabe, University of South Carolina) were directed against the purified collagenous fractions from summer samples. Immunocytochemical techniques were subsequently employed at the electron microscope level and localization of this collagen fraction was determined in animals collected throughout the year. The location of the collagenous fraction of the organic matrix was determined from the time of the initial disappearance from spicules in winter to its reappearance during the following spring and summer. Several mechanisms addressing the fate of the collagen during the winter months are discussed. In addition this study also produced the first evidence for extracellular spicule growth in L. virgulata.
Dupree, Jeffrey L., "Localization of a collagenous protein in the organic matrix of spicules from the octocoral Leptogorgia virgulata (Cnidaria: Gorgonacea)" (1992). Master's Theses. 536.